aboutsummaryrefslogtreecommitdiff
path: root/lib/transfer.c
blob: edbff71ffe5994430d7178fb9403ae34c65eb6e5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
/*****************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 2000, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * In order to be useful for every potential user, curl and libcurl are
 * dual-licensed under the MPL and the MIT/X-derivate licenses.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the MPL or the MIT/X-derivate
 * licenses. You may pick one of these licenses.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id$
 *****************************************************************************/

#include "setup.h"

/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>

#include "strequal.h"

#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
#include <winsock.h>
#include <time.h>
#include <io.h>
#else
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
#include <sys/time.h>
#include <sys/resource.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <netdb.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/ioctl.h>
#include <signal.h>

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#ifndef HAVE_SELECT
#error "We can't compile without select() support!"
#endif
#ifndef HAVE_SOCKET
#error "We can't compile without socket() support!"
#endif

#endif

#include "urldata.h"
#include <curl/curl.h>
#include <curl/types.h>
#include "netrc.h"

#include "hostip.h"
#include "transfer.h"
#include "sendf.h"
#include "speedcheck.h"
#include "getpass.h"
#include "progress.h"
#include "getdate.h"
#include "http.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

/* The last #include file should be: */
#ifdef MALLOCDEBUG
#include "memdebug.h"
#endif

#ifndef min
#define min(a, b)   ((a) < (b) ? (a) : (b))
#endif

/* Parts of this function was written by the friendly Mark Butler
   <butlerm@xmission.com>. */

CURLcode static
Transfer(struct connectdata *c_conn)
{
  ssize_t nread;                /* number of bytes read */
  int bytecount = 0;            /* total number of bytes read */
  int writebytecount = 0;       /* number of bytes written */
  long contentlength=0;         /* size of incoming data */
  struct timeval start = Curl_tvnow();
  struct timeval now = start;   /* current time */
  bool header = TRUE;		/* incoming data has HTTP header */
  int headerline = 0;		/* counts header lines to better track the
                                   first one */
  char *hbufp;			/* points at *end* of header line */
  int hbuflen = 0;
  char *str;			/* within buf */
  char *str_start;		/* within buf */
  char *end_ptr;		/* within buf */
  char *p;			/* within headerbuff */
  bool content_range = FALSE;	/* set TRUE if Content-Range: was found */
  int offset = 0;		/* possible resume offset read from the
                                   Content-Range: header */
  int code = 0;			/* error code from the 'HTTP/1.? XXX' line */
  int httpversion = -1;         /* the last digit in the HTTP/1.1 string */

  /* for the low speed checks: */
  CURLcode urg;
  time_t timeofdoc=0;
  long bodywrites=0;
  int writetype;

  /* the highest fd we use + 1 */
  struct UrlData *data;
  struct connectdata *conn = (struct connectdata *)c_conn;
  char *buf;
  int maxfd;

  data = conn->data; /* there's the root struct */
  buf = data->buffer;
  maxfd = (conn->sockfd>conn->writesockfd?conn->sockfd:conn->writesockfd)+1;

  hbufp = data->headerbuff;

  myalarm (0);			/* switch off the alarm-style timeout */

  now = Curl_tvnow();
  start = now;

#define KEEP_READ  1
#define KEEP_WRITE 2

  Curl_pgrsTime(data, TIMER_PRETRANSFER);
  Curl_speedinit(data);

  if((conn->sockfd == -1) &&
     (conn->writesockfd == -1)) {
    /* nothing to read, nothing to write, we're already OK! */
    return CURLE_OK;
  }

  if (!conn->getheader) {
    header = FALSE;
    if(conn->size > 0)
      Curl_pgrsSetDownloadSize(data, conn->size);
  }
  /* we want header and/or body, if neither then don't do this! */
  if(conn->getheader ||
     !data->bits.no_body) {
    fd_set readfd;
    fd_set writefd;
    fd_set rkeepfd;
    fd_set wkeepfd;
    struct timeval interval;
    int keepon=0;

    /* timeout every X second
       - makes a better progressmeter (i.e even when no data is read, the
       meter can be updated and reflect reality)
       - allows removal of the alarm() crap
       - variable timeout is easier
     */

    FD_ZERO (&readfd);		/* clear it */
    if(conn->sockfd != -1) {
      FD_SET (conn->sockfd, &readfd); /* read socket */
      keepon |= KEEP_READ;
    }

    FD_ZERO (&writefd);		/* clear it */
    if(conn->writesockfd != -1) {
      FD_SET (conn->writesockfd, &writefd); /* write socket */
      keepon |= KEEP_WRITE;
    }

    /* get these in backup variables to be able to restore them on each lap in
       the select() loop */
    rkeepfd = readfd;
    wkeepfd = writefd;

    while (keepon) {
      readfd = rkeepfd;		/* set those every lap in the loop */
      writefd = wkeepfd;
      interval.tv_sec = 1;
      interval.tv_usec = 0;

      switch (select (maxfd, &readfd, &writefd, NULL, &interval)) {
      case -1:			/* select() error, stop reading */
#ifdef EINTR
        /* The EINTR is not serious, and it seems you might get this more
           ofen when using the lib in a multi-threaded environment! */
        if(errno == EINTR)
          ;
        else
#endif
          keepon = 0; /* no more read or write */
	continue;
      case 0:			/* timeout */
	break;
      default:
        if((keepon & KEEP_READ) && FD_ISSET(conn->sockfd, &readfd)) {
          /* read! */
          urg = Curl_read(conn, conn->sockfd, buf, BUFSIZE -1, &nread);

          /* NULL terminate, allowing string ops to be used */
          if (0 < (signed int) nread)
            buf[nread] = 0;

          /* if we receive 0 or less here, the server closed the connection and
             we bail out from this! */
          else if (0 >= (signed int) nread) {
            keepon &= ~KEEP_READ;
            break;
          }

          str = buf;		/* Default buffer to use when we write the
                                   buffer, it may be changed in the flow below
                                   before the actual storing is done. */

          /* Since this is a two-state thing, we check if we are parsing
             headers at the moment or not. */
          
          if (header) {
            /* we are in parse-the-header-mode */

            /* header line within buffer loop */
            do {
              int hbufp_index;
              
              str_start = str;	/* str_start is start of line within buf */
              
              end_ptr = strchr (str_start, '\n');
              
              if (!end_ptr) {
                /* no more complete header lines within buffer */
                /* copy what is remaining into headerbuff */
                int str_length = (int)strlen(str);
                
                if (hbuflen + (int)str_length >= data->headersize) {
                  char *newbuff;
                  long newsize=MAX((hbuflen+str_length)*3/2,
                                   data->headersize*2);
                  hbufp_index = hbufp - data->headerbuff;
                  newbuff = (char *)realloc(data->headerbuff, newsize);
                  if(!newbuff) {
                    failf (data, "Failed to alloc memory for big header!");
                    return CURLE_READ_ERROR;
                  }
                  data->headersize=newsize;
                  data->headerbuff = newbuff;
                  hbufp = data->headerbuff + hbufp_index;
                }
                strcpy (hbufp, str);
                hbufp += strlen (str);
                hbuflen += strlen (str);
                break;		/* read more and try again */
              }

              str = end_ptr + 1;	/* move just past new line */

              if (hbuflen + (str - str_start) >= data->headersize) {
                char *newbuff;
                long newsize=MAX((hbuflen+(str-str_start))*3/2,
                                 data->headersize*2);
                hbufp_index = hbufp - data->headerbuff;
                newbuff = (char *)realloc(data->headerbuff, newsize);
                if(!newbuff) {
                  failf (data, "Failed to alloc memory for big header!");
                  return CURLE_READ_ERROR;
                }
                data->headersize= newsize;
                data->headerbuff = newbuff;
                hbufp = data->headerbuff + hbufp_index;
              }

              /* copy to end of line */
              strncpy (hbufp, str_start, str - str_start);
              hbufp += str - str_start;
              hbuflen += str - str_start;
              *hbufp = 0;
              
              p = data->headerbuff;
              
              /* we now have a full line that p points to */
              if (('\n' == *p) || ('\r' == *p)) {
                /* Zero-length line means end of header! */
                if (-1 != conn->size)	/* if known */
                  conn->size += bytecount; /* we append the already read size */


                if ('\r' == *p)
                  p++;		/* pass the \r byte */
                if ('\n' == *p)
                  p++;		/* pass the \n byte */
#if 0 /* headers are not included in the size */
                Curl_pgrsSetDownloadSize(data, conn->size);
#endif
                header = FALSE;	/* no more header to parse! */

                /* now, only output this if the header AND body are requested:
                 */
                writetype = CLIENTWRITE_HEADER;
                if (data->bits.http_include_header)
                  writetype |= CLIENTWRITE_BODY;

                urg = Curl_client_write(data, writetype, data->headerbuff,
                                        p - data->headerbuff);
                if(urg)
                  return urg;

                data->header_size += p - data->headerbuff;


                /*
                 * end-of-headers.
                 *
                 * If we requested a "no body" and this isn't a "close"
                 * connection, this is a good time to get out and return
                 * home.
                 */
                if(!conn->bits.close && data->bits.no_body)
                  return CURLE_OK;

                break;		/* exit header line loop */
              }
              
              if (!headerline++) {
                /* This is the first header, it MUST be the error code line
                   or else we consiser this to be the body right away! */
                if (2 == sscanf (p, " HTTP/1.%d %3d", &httpversion, &code)) {
                  /* 404 -> URL not found! */
                  if (
                      ( ((data->bits.http_follow_location) && (code >= 400))
                        ||
                        (!data->bits.http_follow_location && (code >= 300)))
                      && (data->bits.http_fail_on_error)) {
                    /* If we have been told to fail hard on HTTP-errors,
                       here is the check for that: */
                    /* serious error, go home! */
                    failf (data, "The requested file was not found");
                    return CURLE_HTTP_NOT_FOUND;
                  }
                  data->progress.httpcode = code;
                  data->progress.httpversion = httpversion;
                  if(httpversion == 0)
                    /* Default action for HTTP/1.0 must be to close, unless
                       we get one of those fancy headers that tell us the
                       server keeps it open for us! */
                    conn->bits.close = TRUE;
                }
                else {
                  header = FALSE;	/* this is not a header line */
                  break;
                }
              }
              /* check for Content-Length: header lines to get size */
              if (strnequal("Content-Length", p, 14) &&
                  sscanf (p+14, ": %ld", &contentlength)) {
                conn->size = contentlength;
                Curl_pgrsSetDownloadSize(data, contentlength);
              }
              else if((httpversion == 0) &&
                      conn->bits.httpproxy &&
                      strnequal("Proxy-Connection: keep-alive", p,
                                strlen("Proxy-Connection: keep-alive"))) {
                /*
                 * When a HTTP/1.0 reply comes when using a proxy, the
                 * 'Proxy-Connection: keep-alive' line tells us the
                 * connection will be kept alive for our pleasure.
                 * Default action for 1.0 is to close.
                 */
                conn->bits.close = FALSE; /* don't close when done */
                infof(data, "HTTP/1.0 proxy connection set to keep alive!\n");
              }
              else if (strnequal("Connection: close", p,
                                 strlen("Connection: close"))) {
                /*
                 * [RFC 2616, section 8.1.2.1]
                 * "Connection: close" is HTTP/1.1 language and means that
                 * the connection will close when this request has been
                 * served.
                 */
                conn->bits.close = TRUE; /* close when done */
              }
              else if (strnequal("Transfer-Encoding: chunked", p,
                                 strlen("Transfer-Encoding: chunked"))) {
                /*
                 * [RFC 2616, section 3.6.1] A 'chunked' transfer encoding
                 * means that the server will send a series of "chunks". Each
                 * chunk starts with line with info (including size of the
                 * coming block) (terminated with CRLF), then a block of data
                 * with the previously mentioned size. There can be any amount
                 * of chunks, and a chunk-data set to zero signals the
                 * end-of-chunks. */
                conn->bits.chunk = TRUE; /* chunks coming our way */

                /* init our chunky engine */
                Curl_httpchunk_init(conn);
              }
              else if (strnequal("Content-Range", p, 13)) {
                if (sscanf (p+13, ": bytes %d-", &offset) ||
                    sscanf (p+13, ": bytes: %d-", &offset)) {
                  /* This second format was added August 1st 2000 by Igor
                     Khristophorov since Sun's webserver JavaWebServer/1.1.1
                     obviously sends the header this way! :-( */
                  if (data->resume_from == offset) {
                    /* we asked for a resume and we got it */
                    content_range = TRUE;
                  }
                }
              }
              else if(data->cookies &&
                      strnequal("Set-Cookie: ", p, 11)) {
                Curl_cookie_add(data->cookies, TRUE, &p[12]);
              }
              else if(strnequal("Last-Modified:", p,
                                strlen("Last-Modified:")) &&
                      (data->timecondition || data->bits.get_filetime) ) {
                time_t secs=time(NULL);
                timeofdoc = curl_getdate(p+strlen("Last-Modified:"), &secs);
                if(data->bits.get_filetime)
                  data->progress.filetime = timeofdoc;
              }
              else if ((code >= 300 && code < 400) &&
                       (data->bits.http_follow_location) &&
                       strnequal("Location: ", p, 10)) {
                /* this is the URL that the server advices us to get instead */
                char *ptr;
                char *start=p;
                char backup;

                start += 10; /* pass "Location: " */
                ptr = start; /* start scanning here */
                /* scan through the string to find the end */
                while(*ptr && !isspace((int)*ptr))
                  ptr++;
                backup = *ptr; /* store the ending letter */
                *ptr = '\0';   /* zero terminate */
                conn->newurl = strdup(start); /* clone string */
                *ptr = backup; /* restore ending letter */
              }

              writetype = CLIENTWRITE_HEADER;
              if (data->bits.http_include_header)
                writetype |= CLIENTWRITE_BODY;

              urg = Curl_client_write(data, writetype, p, hbuflen);
              if(urg)
                return urg;

              data->header_size += hbuflen;
              
              /* reset hbufp pointer && hbuflen */
              hbufp = data->headerbuff;
              hbuflen = 0;
            }
            while (*str);		/* header line within buffer */

            /* We might have reached the end of the header part here, but
               there might be a non-header part left in the end of the read
               buffer. */

            if (!header) {
              /* the next token and forward is not part of
                 the header! */

              /* we subtract the remaining header size from the buffer */
              nread -= (str - buf);
            }

          }			/* end if header mode */

          /* This is not an 'else if' since it may be a rest from the header
             parsing, where the beginning of the buffer is headers and the end
             is non-headers. */
          if (str && !header && ((signed int)nread > 0)) {
            
            if(0 == bodywrites) {
              /* These checks are only made the first time we are about to
                 write a piece of the body */
              if(conn->protocol&PROT_HTTP) {
                /* HTTP-only checks */
                if (conn->newurl) {
                  /* abort after the headers if "follow Location" is set */
                  infof (data, "Follow to new URL: %s\n", conn->newurl);
                  return CURLE_OK;
                }
                else if (data->resume_from &&
                         !content_range &&
                         (data->httpreq==HTTPREQ_GET)) {
                  /* we wanted to resume a download, although the server
                     doesn't seem to support this and we did this with a GET
                     (if it wasn't a GET we did a POST or PUT resume) */
                  failf (data, "HTTP server doesn't seem to support "
                         "byte ranges. Cannot resume.");
                  return CURLE_HTTP_RANGE_ERROR;
                }
                else if(data->timecondition && !data->range) {
                  /* A time condition has been set AND no ranges have been
                     requested. This seems to be what chapter 13.3.4 of
                     RFC 2616 defines to be the correct action for a
                     HTTP/1.1 client */
                  if((timeofdoc > 0) && (data->timevalue > 0)) {
                    switch(data->timecondition) {
                    case TIMECOND_IFMODSINCE:
                    default:
                      if(timeofdoc < data->timevalue) {
                        infof(data,
                              "The requested document is not new enough\n");
                        return CURLE_OK;
                      }
                      break;
                    case TIMECOND_IFUNMODSINCE:
                      if(timeofdoc > data->timevalue) {
                        infof(data,
                              "The requested document is not old enough\n");
                        return CURLE_OK;
                      }
                      break;
                    } /* switch */
                  } /* two valid time strings */
                } /* we have a time condition */

                if(!conn->bits.close) {
                  /* If this is not the last request before a close, we must
                     set the maximum download size to the size of the expected
                     document or else, we won't know when to stop reading! */
                  if(-1 != conn->size)
                    conn->maxdownload = conn->size;

                  /* What to do if the size is *not* known? */
                }

              } /* this is HTTP */
            } /* this is the first time we write a body part */
            bodywrites++;

            if(conn->bits.chunk) {
              /*
               * Bless me father for I have sinned. Here comes a chunked
               * transfer flying and we need to decode this properly.  While
               * the name says read, this function both reads and writes away
               * the data. The returned 'nread' holds the number of actual
               * data it wrote to the client.  */
              CHUNKcode res =
                Curl_httpchunk_read(conn, str, nread, &nread);

              if(CHUNKE_OK < res) {
                failf(data, "Receeived problem in the chunky parser");
                return CURLE_READ_ERROR;
              }
              else if(CHUNKE_STOP == res) {
                /* we're done reading chunks! */
                keepon &= ~KEEP_READ; /* read no more */

                /* There are now possibly N number of bytes at the end of the
                   str buffer that weren't written to the client, but we don't
                   care about them right now. */
              }
              /* If it returned OK, we just keep going */
            }

            if(conn->maxdownload &&
               (bytecount + nread >= conn->maxdownload)) {
              nread = conn->maxdownload - bytecount;
              if((signed int)nread < 0 ) /* this should be unusual */
                nread = 0;
              keepon &= ~KEEP_READ; /* we're done reading */
            }

            bytecount += nread;

            Curl_pgrsSetDownloadCounter(data, (double)bytecount);
            
            if(! conn->bits.chunk) {
              /* If this is chunky transfer, it was already written */
              urg = Curl_client_write(data, CLIENTWRITE_BODY, str, nread);
              if(urg)
                return urg;
            }

          } /* if (! header and data to read ) */
        } /* if( read from socket ) */

        if((keepon & KEEP_WRITE) && FD_ISSET(conn->writesockfd, &writefd)) {
          /* write */

          char scratch[BUFSIZE * 2];
          int i, si;
          size_t bytes_written;

          if(data->crlf)
            buf = data->buffer; /* put it back on the buffer */

          nread = data->fread(buf, 1, conn->upload_bufsize, data->in);

          /* the signed int typecase of nread of for systems that has
             unsigned size_t */
          if ((signed int)nread<=0) {
            /* done */
            keepon &= ~KEEP_WRITE; /* we're done writing */
            break;
          }
          writebytecount += nread;
          Curl_pgrsSetUploadCounter(data, (double)writebytecount);            

          /* convert LF to CRLF if so asked */
          if (data->crlf) {
            for(i = 0, si = 0; i < (int)nread; i++, si++) {
              if (buf[i] == 0x0a) {
                scratch[si++] = 0x0d;
                scratch[si] = 0x0a;
              }
              else {
                scratch[si] = buf[i];
              }
            }
            nread = si;
            buf = scratch; /* point to the new buffer */
          }

          /* write to socket */
          urg = Curl_write(conn, conn->writesockfd, buf, nread,
                           &bytes_written);

          if(nread != bytes_written) {
            failf(data, "Failed uploading data");
            return CURLE_WRITE_ERROR;
          }

        }

        break;
      }

      now = Curl_tvnow();
      if(Curl_pgrsUpdate(data))
        urg = CURLE_ABORTED_BY_CALLBACK;
      else
        urg = Curl_speedcheck (data, now);
      if (urg)
	return urg;

      if(data->progress.ulspeed > conn->upload_bufsize) {
        /* If we're transfering more data per second than fits in our buffer,
           we increase the buffer size to adjust to the current
           speed. However, we must not set it larger than BUFSIZE. We don't
           adjust it downwards again since we don't see any point in that!
        */
        conn->upload_bufsize=(long)min(data->progress.ulspeed, BUFSIZE);
      }

      if (data->timeout && (Curl_tvdiff (now, start) > data->timeout)) {
	failf (data, "Operation timed out with %d out of %d bytes received",
	       bytecount, conn->size);
	return CURLE_OPERATION_TIMEOUTED;
      }
    }
  }
  if(!(data->bits.no_body) && contentlength &&
     (bytecount != contentlength)) {
    failf(data, "transfer closed with %d bytes remaining to read",
          contentlength-bytecount);
    return CURLE_PARTIAL_FILE;
  }
  if(Curl_pgrsUpdate(data))
    return CURLE_ABORTED_BY_CALLBACK;

  if(conn->bytecountp)
    *conn->bytecountp = bytecount; /* read count */
  if(conn->writebytecountp)
    *conn->writebytecountp = writebytecount; /* write count */

  return CURLE_OK;
}

CURLcode Curl_perform(CURL *curl)
{
  CURLcode res;
  struct UrlData *data = (struct UrlData *)curl;
  struct connectdata *conn=NULL;
  bool port=TRUE; /* allow data->use_port to set port to use */

  Curl_pgrsStartNow(data);

  do {
    Curl_pgrsTime(data, TIMER_STARTSINGLE);
    res = Curl_connect(data, &conn, port);
    if(res == CURLE_OK) {
      res = Curl_do(conn);
      if(res == CURLE_OK) {
        res = Transfer(conn); /* now fetch that URL please */
        if(res == CURLE_OK)
          res = Curl_done(conn);
      }

      if((res == CURLE_OK) && conn->newurl) {
        /* Location: redirect
 
           This is assumed to happen for HTTP(S) only!
        */
        char prot[16]; /* URL protocol string storage */
        char letter;   /* used for a silly sscanf */

        port=TRUE; /* by default we use the user set port number even after
                      a Location: */

	if (data->maxredirs && (data->followlocation >= data->maxredirs)) {
	  failf(data,"Maximum (%d) redirects followed", data->maxredirs);
#ifdef USE_OLD_DISCONNECT
          curl_disconnect(c_connect);
#endif
          res=CURLE_TOO_MANY_REDIRECTS;
	  break;
	}

        /* mark the next request as a followed location: */
        data->bits.this_is_a_follow = TRUE;

        data->followlocation++; /* count location-followers */

        if(data->bits.http_auto_referer) {
          /* We are asked to automatically set the previous URL as the
             referer when we get the next URL. We pick the ->url field,
             which may or may not be 100% correct */

          if(data->free_referer) {
            /* If we already have an allocated referer, free this first */
            free(data->referer);
          }

          data->referer = strdup(data->url);
          data->free_referer = TRUE;          /* yes, free this later */
          data->bits.http_set_referer = TRUE; /* might have been false */
        }

        if(2 != sscanf(conn->newurl, "%15[^:]://%c", prot, &letter)) {
          /***
           *DANG* this is an RFC 2068 violation. The URL is supposed
           to be absolute and this doesn't seem to be that!
           ***
           Instead, we have to TRY to append this new path to the old URL
           to the right of the host part. Oh crap, this is doomed to cause
           problems in the future...
          */
          char *protsep;
          char *pathsep;
          char *newest;

          /* protsep points to the start of the host name */
          protsep=strstr(data->url, "//");
          if(!protsep)
            protsep=data->url;
          else {
            port=FALSE; /* we got a full URL and thus we should not obey the
                           port number that might have been set by the user
                           in data->use_port */

            protsep+=2; /* pass the slashes */
          }

          if('/' != conn->newurl[0]) {
            /* First we need to find out if there's a ?-letter in the URL,
               and cut it and the right-side of that off */
            pathsep = strrchr(protsep, '?');
            if(pathsep)
              *pathsep=0;

            /* we have a relative path to append to the last slash if
               there's one available */
            pathsep = strrchr(protsep, '/');
            if(pathsep)
              *pathsep=0;
          }
          else {
            /* We got a new absolute path for this server, cut off from the
               first slash */
            pathsep = strchr(protsep, '/');
            if(pathsep)
              *pathsep=0;
          }

          newest=(char *)malloc( strlen(data->url) +
                                 1 + /* possible slash */
                                 strlen(conn->newurl) + 1/* zero byte */);

          if(!newest)
            return CURLE_OUT_OF_MEMORY;
          sprintf(newest, "%s%s%s", data->url, ('/' == conn->newurl[0])?"":"/",
                  conn->newurl);
          free(conn->newurl);
          conn->newurl = newest;
        }
        else {
          /* This is an absolute URL, don't use the custom port number */
          port = FALSE;
        }

        if(data->bits.urlstringalloc)
          free(data->url);
      
        /* TBD: set the URL with curl_setopt() */
        data->url = conn->newurl;
        conn->newurl = NULL; /* don't show! */
        data->bits.urlstringalloc = TRUE; /* the URL is allocated */

        infof(data, "Follows Location: to new URL: '%s'\n", data->url);

        /*
         * We get here when the HTTP code is 300-399. We need to perform
         * differently based on exactly what return code there was.
         * Discussed on the curl mailing list and posted about on the 26th
         * of January 2001.
         */
        switch(data->progress.httpcode) {
        case 300: /* Multiple Choices */
        case 301: /* Moved Permanently */
        case 302: /* Found */
        case 306: /* Not used */
        case 307: /* Temporary Redirect */
        default:  /* for all unknown ones */
          /* These are explicitly mention since I've checked RFC2616 and they
           * seem to be OK to POST to.
           */
          break;
        case 303: /* See Other */
          /* Disable both types of POSTs, since doing a second POST when
           * following isn't what anyone would want! */
          data->bits.http_post = FALSE;
          data->bits.http_formpost = FALSE;
          data->httpreq = HTTPREQ_GET; /* enfore GET request */
          infof(data, "Disables POST\n");
          break;
        case 304: /* Not Modified */
          /* 304 means we did a conditional request and it was "Not modified".
           * We shouldn't get any Location: header in this response!
           */
          break;
        case 305: /* Use Proxy */
          /* (quote from RFC2616, section 10.3.6):
           * "The requested resource MUST be accessed through the proxy given
           * by the Location field. The Location field gives the URI of the
           * proxy.  The recipient is expected to repeat this single request
           * via the proxy. 305 responses MUST only be generated by origin
           * servers."
           */
          break;
        }
#ifdef USE_OLD_DISCONNECT
        curl_disconnect(c_connect);
#endif
        continue;
      }

#ifdef USE_OLD_DISCONNECT
      curl_disconnect(c_connect);
#endif
    }
    break; /* it only reaches here when this shouldn't loop */

  } while(1); /* loop if Location: */

  if(conn->newurl) {
    free(conn->newurl);
    conn->newurl = NULL;
  }

  return res;
}


CURLcode 
Curl_Transfer(struct connectdata *c_conn, /* connection data */
              int sockfd,	/* socket to read from or -1 */
              int size,		/* -1 if unknown at this point */
              bool getheader,	/* TRUE if header parsing is wanted */
              long *bytecountp,	/* return number of bytes read or NULL */
              int writesockfd,  /* socket to write to, it may very well be
                                   the same we read from. -1 disables */
              long *writebytecountp /* return number of bytes written or
                                       NULL */
              )
{
  struct connectdata *conn = (struct connectdata *)c_conn;
  if(!conn)
    return CURLE_BAD_FUNCTION_ARGUMENT;

  /* now copy all input parameters */
  conn->sockfd = sockfd;
  conn->size = size;
  conn->getheader = getheader;
  conn->bytecountp = bytecountp;
  conn->writesockfd = writesockfd;
  conn->writebytecountp = writebytecountp;

  return CURLE_OK;

}